Thermoelectric generator and pilot burner



Jan. 28, 1958 P. A. DE LEON, JR 1 2532119564 THERMOELECTRIC GENERATOR AND PILOT BURNER Filed May 1'7. 1956.

............................. a E k z y r '7\\ Q l INVENTOR. P4141 A. DeLeon,

United States Patent M THERMOELECTRIC GENERATOR AND PILOT BURNER Paul A. De Leon, Jr., Brentwood, Mo., assignor to Base Inc., Milwaukee, Wis., a corporation of Wisconsin Application May 17, 1956, Serial No. 585,501

9 Claims. (Cl. 136-4) This invention relates in general to a thermoelectric generator and pilot burner and more particularly to a unitary thermoelectric generator, lead and pilot burner assembly.

In the control of gaseous fuel, constant burning pilot burners are often used to ignite relatively larger main burners and thermoelectric generators are associated therewith to detect the presence of the flame at the pilot burner for safety reasons.

It is a characteristic of certain thermoelectric elements that they are susceptible of breakdown when exposed to gaseous fuel or to air when said element is subjected to the relatively high temperatures of the flame. 0n the other hand certain dissimilar thermoelements are not so affected. In order to avoid deleterious effects on the susceptible type of thermoelements, they are often placed within the non-susceptible elements in a coaxial arrangement with the inner element preferably sealed from contact with the fuel and from the air. Attached to the sealed thermoelectric unit is a lead connection means leading to a device for safety shut-off or other purposes and of the type which are energized by or utilize the thermoelectric power. Heretofore it has been necessary that a separate pilot gas pipe be run to a pilot burner along with the thermoelectric leads with resultant problems of how to handle the extra mass in what is often cramped space together with the problems of mounting both the pilot burner relative to the generator and the pilot burner relative to the main burner.

It is a general object of this invention to provide a device wherein the thermoelectric generator, lead and pilot burner are a unitary assembly to facilitate handling, mounting and manufacture thereof.

Another object of the invention is to provide a device of the type above described which maintains the inner element free from contact with the fluid fuel and from the air.

Another object of the invention is to provide a device of the type aforementioned which is adapted to have the pilot burner fuel metering means at the end of the lead assembly furthest away from the pilot burner.

Another object of the present invention is to provide a device of the aforementioned general characteristics which is well adapted for low consumption applications, is low in mass, is multi-positional, is easily mounted, and is readily adapted for mass manufacture.

The novel features that are characteristic of the invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof will best be .understood by the following description of a specific embodiment when read in connection with accompanying drawings, in which:

Figure l is a view, partially in section, of an embodiment of the unitary thermoelectric generator, lead and pilot burner assembly;

2,821,564 Patented Jan. 28, 1958 Figure 2 is a view, partially in section, of a modified form of the invention;

Figure 3 is a view of an alternative form of pilot burner tube, said form being similar to the form shown in Figure 2; and

Figure 4 is an end view of the embodiment shown in Figure 3.

Referring now in detail to the drawings, the embodiment of the invention shown in Figure 1 shows a unitary assembly which comprises the thermoelectric generator portion 9, the lead conductor means 8, and the fuel supply and burner means. The thermoelectric generator 9 comprises a generally cylindrical outer thermoelement 12 having a closed end and a suitable dissimilar inner thermoelement 14 which is disposed within and firmly welded at said closed end to provide the hot junction of the generator as is well understood in the art. The outer element 12 may be made of any suitable material, such as for example, stainless steel, which exhibits good durability characteristics in field appplications. The inner thermoelement 14 may be formed of any of several metallic and semi-metallic materials which will exhibit the necessary characteristics when joined with the outer thermoelement to produce an E. M. F. when a differential in temperature exists between the hot and cold junctions of the generator as well known in the art. The open end of the outer thermoelement 12 may be telescopingly fitted into and sealingly engaged by a relatively larger tubular electrically conductive member 18 to form one of the cold junctions 16 of the thermoeleceric generator. The conductor member 18 may be formed of brass or other material that is electrically conductive, said member also being well adapted to receive any suitable or desired mounting fittings to mount the assembly relative to the main burner (not shown).

The lead assembly 8 comprises the conductor 18 and an elongated electrically conductive tubular member 20 which may be telescopically fitted within and sealingly joined to the other end of the conductor member 18 to form the outer lead conductor of the generator 9. Within the outer conductor tubing 20, and forming the other conductor of the generator, is an insulated inner conductor 22 which is joined to the inner thermoelement 14 to form the second cold junction 17 of the generator. The inner and outer conductors 20 and 22 may be composed of for example copper or other suitable electrically conductive material.

The ends of the inner and outer conductors 22 and 20 away from the generator 9 are suitably formed for quick detachable electrical connection with a device which utilizes the power generated by said generator 9. To this end, the inner conductor 22 is preferably formed with an enlarged terminal tip 22a for suitable connection with an inner conductor 22b associated with the device to which the power is being delivered. Surrounding the outer tubing 20 is a suitable threaded connector fitting 20a which is adapted to conducti'vely engage the outer conductor 20 and the device to be powered. It is to be noted that the electrical connection of outer conductor 20 is such that upon tightening of fitting 20a, insulating material 19 which is interposed between the tip 22a and the end of the conductor 20, seals said end so as to prevent the entry of air thereto. It is thus apparent that a sealed enclosure is formed by the outer thermoelement, the outer conductors 18 and 20 and the sealing material 19.

Disposed within the enclosure formed by the outer members of the assembly is a small fuel supply tube 30. One end of tube 30 extends through a suitable aperture in the outer conductor 12 to form a pilot burner flame port 31. The tube may be formed of any suitable material that will withstand the temperature at which the flame port is subjected, one such material being stainless steel tubing. It is to be noted that the aperture in the outer thermoelement 12 is formed so that upon ignition of fuel emanating from tube 30, the flame will be operable to heat the hot junction 15 of the generator. The tube 30 and the marginal surface of the aperture are preferably suitably sealed relative to each other such as by welding or other means that will withstand high temperatures.

The other end of supply tube 30 is preferably disposed so as to sealingly extend through the conductor for coaction with a suitable inlet fitting 23 which may be fixed to the outer surface of conductor 22. Anterior of the inlet fitting 23 and coacting therewith is a spud connection 25 having integral fuel metering means 26 contained therein. A fuel supply pipe 24 may be connected to a suitable source and to said spud 25 by suitable fittings as well understood in the art. The described arrangement affords the ready inspection and removal of the spud 25 inasmuch as this portion of the integral generator, lead and pilot burner assembly is most likely to be disposed outside of the combustion area. It is to be noted that the enclosure formed by the outer thermoelement and conductors 18 and 20 is sealed at both the ingress and egress of tube 30 which serves to maintain the isolation of the inner thermoelectric element from fuel and from air when the assembly is in use.

Figure 2 shows a modification of the generator presented in Figure l in that the pilot supply tube 30' sealingly extends outwardly through a wall portion of the conductor 18' rather than through the outer thermoelement of the generator. This has the advantage of allowing a relatively larger inner thermoelement 14' as compared to the outer element 12' which in certain applications give better electrical balancing of the thermoelectric system.

Figure 3 shows an alternative form of flame port arrangement, the rest of the apparatus being similar to Figure 2 in that a gas tube 50 sealingly extends through an aperture in the conductor 18. The portion of the tube 50 posterior of the egress from the conductor may be formed so that it will encircle the outer element 14', and a plurality of small apertures forming flame ports 51 may be arcuately disposed around the axis of the outer element 14' so as to present a ring of flame upon the hot junction of the generator upon ignition fuel emanating from said ports.

Although specific embodiments of the invention have been shown and described, it is with full awareness that many further modifications thereof are possible. The invention therefore is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

What is claimed as the invention is:

1. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermoelement, an inner thermoelement disposed within said tubular thermoelement and joined to one thereof to form a first thermojunction, tubular conductor means joined to said outer tubular thermoelement to form a second thermojunction, an inner conductor extending Within said tubular conductor means and joined to said inner thermoelement to form a third thermojunction, said tubular conductor means and tubular thermoelement forming a casing, and said tubular conductor means and inner conductor forming a lead circuit connection for said thermoelements, said casing being formed with an apertured wall portion, and a fuel pipe disposed within said tubular conductor means and having one end sealingly extending through said casing aperture and terminating in a flame port disposed in coacting proximity to said first thermojunction for the burning of fuel thereat.

2. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermo element, an inner thermoelement disposed Within said tubular thermoelement and joined to one end thereof to form 4 a first thermojunction, tubular conductor means comprising first and second tubular conductors, said first tubular conductor being joined to said outer tubular thermoelement to form a second thermojunction, said first tubular conductor member being joined to said second tubular conductor, said first and second tubular conductors together with said outer thermoelement defining an enclosure, an inner conductor extending within said tubular conductor means and joined to said inner thermoelement to form an enclosed third thermojunction, said tubular conductor means and said inner conductor forming a lead circuit connection, and a fuel pipe disposed within said enclosure and having one end sealingly extending through a wall portion thereof and terminating in an outlet disposed in coacting proximity to said first thermojunction for the burning of fuel thereat.

3. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermoelement having a closed end, an inner thermoelement disposed within said tubular thermoelement and joined to said closed end to form a first thermojunction, tubular conductor means comprising first and second tubular conductors, said first tubular conductor being sealingly joined to said outer tubular thermoelement to form a second thermojunction, said first tubular conductor member also being sealingly joined to said second tubular conductor, said second tubular conductor being provided with a sealed portion to define a sealed enclosure with said first tubular conductor and said outer thermoelement, an inner conductor extending Within said tubular conductor means and joined to said inner thermoelement to form an enclosed third thermojunction, said tubular conductor means and said inner conductor forming a lead circuit connection, and a fuel pipe disposed within said sealed enclosure and having one end sealingly extending through a wall portion thereof and terminating in an external flame port disposed in coacting proximity to said first thermojunction for the burning of fuel thereat.

4. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermoelement having a closed end, an inner thermoelement disposed within said tubular thermoelement and joined to said end thereof to form a first thermojunction, a tubular conductor means coaxially and sealingly joined at one end to said outer tubular thermoelement to form a second thermojunction, an inner conductor extending within said tubular conductor and joined to said inner thermoelement to form an enclosed third thermojunction, said tubular conductor means and said inner conductor being sealed relative to each other at the end opposite from their connections with said thermoelements to thereby afiord a sealed tubular enclosure, said tubular conductor and said inner conductor forming a lead circuit connection, and a fuel pipe disposed within said tubular enclosure and sealingly extending through a wall portion of said tubular enclosure whereby the outlet is disposed in coacting proximity to said first thermojunction, said fuel pipe also sealingly extending through said tubular enclosure for connection with suitable inlet means wherefore upon fuel being admitted to said fuel pipe, said outlet is operable to be a pilot burner and a flame port for said thermoelectric generator and said inner thermoelement is isolated from contact with said fuel.

5. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermoelement, an inner thermoelement disposed within said tubular thermoelement and joined to one end thereof to form a first thermojunction, tubular conductor means joined to said outer tubular thermoelement to form a second thermojunction, an inner conductor extending within said tubular conductor means and joined to said inner thermoelement to form a third thermojunction, said tu ular conductor means and tubular thermoelement forming a casing, and said tubular conductor means and inner conductor forming a lead circuit connection for said thermoelements, said casing being formed with a pair of apertures, a fuel pipe disposed within said tubular conductor means, and sealingly extending through one of said apertures, external fuel inlet means on said casing connected to said fuel pipe and provided with fuel metering means, said fuel pipe also sealingly extending through said other aperture and terminating in a flame port disposed in coacting proximity to said first thermojunction for the burning of fuel thereat.

6. In a unitary thermoelectric generator, lead and low consumption pilot burner assembly, comprising an outer tubular thermoelement, an inner thermoelement disposed within said tubular thermoelement and joined to one end thereof to form a first thermojunction, tubular conductor means joined to said outer tubular thermoelement to form a second thermojunction, an inner conductor extending within said tubular conductor means and joined to said inner thermoelement to form a third thermojunction, said tubular conductor means and tubular thermoelement forming a casing, and said tubular conductor means and inner conductor forming a lead circuit connection for said thermoelements, said casing being formed with an apertured wall portion, and a fuel pipe disposed within said tubular conductor means and having one end sealingly extending through said casing aperture, said pipe terminating in a portion external to said casing and formed with a plurality of flame ports encircling said outer conductor in coacting proximity to said first thermojunction for the burning of fuel thereat.

7. In a unitary thermoelectric generator, lead assembly and low consumption pilot burner, for fluid fuel burning apparatus, comprising a first thermoelement, a second thermoelement disposed within said first thermoelement and joined to one end thereof to form a first thermojunction, a first conductor means joined to said first thermoelement to form a second thermojunction, a second conductor extending within said first conductor means and joined to said second thermoelement to form an enclosed third thermojunction, said first conductor means and said second conductor forming a lead circuit connection, and a fuel pipe disposed within said first conductor means and having one end sealingly extending through a wall portion thereof and terminating in a frame port in coacting proximity to said first thermojunction, said fuel pipe isolating said second thermoelement from contact with the fluid fuel supplied to said flame port.

8. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermoelement, an inner thermoelement disposed within said tubular thermoelement and joined to one thereof to form a first thermojunction, tubular conductor means joined to said outer tubular thermoelement to form a second thermojunction, an inner conductor extending within said tubular conductor means and joined to said inner thermoelement to form a third thermojunction, said tubular conductor means and tubular thermoelement forming a casing, and said tubular conductor means and inner conductor forming a lead circuit connection for said thermoelements, said casing being formed with an apertured wall portion in proximity to said first thermojunction, and a fuel pipe disposed within said tubular conductor means and having one end sealingly attached to the margin of said casing aperture and forming a flame port at said aperture for the burning of fuel in coacting proximity to said first thermojunction while isolating said inner thermoelement from contact with the fuel supplied to said flame port.

9. In a unitary thermoelectric generator, lead and pilot burner assembly, comprising an outer tubular thermoelement, an inner thermoelement disposed within said tubular thermoelement and joined to one end thereof to form a first thermojunction, tubular conductor means comprising first and second tubular conductors, said first tubular conductor being joined to said outer tubular thermoelement to form a second thermojunction, said first tubular conductor member being joined to said second tubular conductor, said first and second tubular con ductors together with said outer thermoelement defining an enclosure, an inner conductor extending within said tubular conductor means and joined to said inner thermoelement to form an enclosed third thermojunction, said tubular conductor means and said inner conductor forming a lead circuit connection, and a fuel pipe disposed within said enclosure and having one end sealingly extending through said first tubular conductor and terminating in an outlet disposed in enacting proximity to said first thermojunction for the burning of fuel thereat.

References Cited in the file of this patent UNITED STATES PATENTS 2,303,183 Wasson Nov. 24, 1942 2,526,112 Biggle Oct. 17, 1950 2,649,490 Greenmayer Aug. 18, 1953 2,649,524 Perl Aug. 18, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTEON Patent No., 2,821,564 January 28, 1958 Paul A, De Leon, Jr,

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 5'7, for "one thereof" read one end thereof column. 6, line 3, for "one thereof" read m one end thereof Signed and sealed this 25th day of March 1958.,

KARL Ha AXLINE ROBERT C WATSON Attesting Officer Conznissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N00 12,821,564 January 28, 1958 Paul A. De Leon, Jr

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 57, for "one thereof" read one end thereof column 6, line 3, for "one thereof" read w one end thereof Signed and sealed this 25th day of March 1958 fb gtz KARL H AXBINE ROBERT C WATSON Attesting Officer Corrmissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Noa 2,821,564 January 28, 1958 Paul A., De Leon, Jr.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 57, for "one thereof" read one end thereof column 6, line 3, for "one thereof" read one end thereof Signed and sealed this 25th day of March 1958.,

KARL Ha AXLINE ROBERT C WATSON Attesting Officer Commissioner of Patents 

